The present disclosure relates to ratchet wrenches. Ratchet wrenches typically embody a handle portion and a head portion, wherein the head portion houses a ratchet mechanism capable of rotating about an axis. A drive motor may be positioned in the handle portion to drive the ratchet mechanism. These drive motors may be pneumatic, however other motors may also be utilized.
A ratchet drive may be positioned within the head portion and includes a square drive on which sockets may be attached. The head portion may house a reciprocating yoke capable of rotating the ratchet mechanism. The yoke reciprocates between movement in a first direction and movement in a second direction opposite the first direction to turn the ratchet mechanism. The yoke may comprise gear cogs, teeth, serrations, or other engagement portions, herein referred to generally as yoke teeth. Additionally, the ratchet mechanism may include one or more pawls pivotally positioned within the head and capable of selectively engaging the yoke teeth when the reciprocating yoke moves in the first direction and ratcheting over the yoke teeth when the yoke moves in the second direction opposite the first direction. In reversing ratchet wrenches, the pawl may be selectively engageable with the yoke teeth when the yoke moves in the first direction or the second direction enabling clockwise or counterclockwise rotation of the drive member respectively.
When the yoke moves engaged with the pawl in the first direction, the ratchet drive rotates about its axis in the first direction. Then, when the yoke moves in the second direction, the pawl ratchets over the yoke and the ratchet drive mechanism may be held in position relative to the head portion. While the yoke moves in the second direction, certain ratchet wrenches may keep the ratchet drive in place using a spring. The spring creates a frictional force that is typically referred to as head tension or tension. In the past, coil springs, wave springs or wave washers, and Bellville washers have been used to urge the ratchet mechanism against a portion of the head to provide head tension.
For coil springs, the amount of tension in the head portion of the ratchet wrench may be increased by either increasing the outside diameter of the coil spring and/or increasing the wire size, increasing the spring constant. However, the increase in the diameter of a coil spring, which may be caused by an increase in wire size, may require an increase in the diameter of the recess in which the spring is positioned in the ratchet drive mechanism. Increasing the diameter of the recess in the ratchet drive mechanism may weaken the area around the recess, causing increased stress on the ratchet mechanism.
The disclosed ratchet wrench mechanism maintains a greater tension or frictional force in the head portion of the ratchet wrench without increasing the diameter of the coil spring or size of the recess in the body of the ratchet mechanism. Further, the presently disclosed spring assembly in the ratchet wrench maintains a more stable force throughout the life of the tool and prolongs the life of the tool.
The ratchet wrench of the present disclosure comprising a handle portion, a head portion operably connected to the handle portion, a drive body comprising at least one pawl and at least one spring aperture positioned in the head portion, a yoke comprising a plurality of teeth positioned within the head portion capable of reciprocating between a first direction with the at least one pawl operatively engaging one or more teeth and a second direction with the at least one pawl disengaged from the teeth. The ratchet may further comprise a spring assembly positioned in at least one spring aperture capable of retaining the drive body relative to the head portion when the yoke reciprocates in the second direction with the at least one pawl disengaged from the teeth. The spring assembly may comprise a spring and a stabilizer cooperatively positioned with the spring.